Non-scatterable glass and the process of making it.



- UNI TED STATES PATENT OFFICE.

ANDRE ROOSEVELT, OF NEW YORK, N. Y., ASSIGNOR TO GLASS FOUNDERS CORPORA-TION, OF NEW YOBK, Y., A CORPORATION OF NEW YORK.

1,210,997. In Drawing;

To all whom it may concern a Be it known that 1, Armin ROOSE EL acitizen of the United States, and a resident of the borough of,Richmond, 'eity and State of New York, have invented certain new anuseful Improvements in Non-Scatter .able Glassand the Processes ofMaking It,.

of which the following is a specification.

My invention relates to a composite glass sheet composed ofordinaryg'lass combined with a transparent cellulose material in such away transparent, will be reinforced and strengthened as oompared'withordinary glass and will not shatter when broken asby a blow, so as tocausepieces thereof to scatter. Such a glass has obviously many valuableapplications among which its use as a windshield for automobiles ",may'be mentioned.

Theobject of my inventionisto provide a glass ofthe kind describedinwhich'the va rious laminae are adherent to each other to a] highdegree, in which the transparency of the "ordinary glass, iii-impairedat all, is

aifected only slightly, and in which the cha.r.

aoteri'stics of strength and non-scatterability are presentito a maximumdegree,

In the operation of the process of my in vention a sheet of ordinaryglassis first cleaned thorcugh1y,thec1ean surface is then coated with -asolution of gelatin or other suitable transparent gelatinous substanceand thereu on a solution of celluloseimaterial is apiz'led at least oneof the solvents employed a solv' elfiti the gelatin and the cellu' sematerial The glass sheet may beicleaned with the aid of any suitablescouring material such a as a scouring soap and the operationmaybeperformed either by hand or by a 11130111118 It is important, it thebest results are desired,-

that dirt of any kind-and especiallythat of a greasy nature be whollyremoved and that i 'a begiventothe glass as by rubbing with a clean, dryclothm A gelatinsolution is now prepared in any suitable way, as forexample-by dissolving pieces of sheet gelatin initormic acid (sp. gr.1.20),-the best proportions lmownto mebeing 7 parts gelatin to 93 partstormicacid, and then. filtering through a filter paper. Instead offormic acid any other solvent of gelatin may be used whichalso hassolvent action upon the Specification of Letters latcnt.

that the; final product, whileaction upon both tering material by airpressure, and

method l 4 AND THE IE 'BOCESS OF MAKING IT.

atented Jan. 2, 1917.

Application filed June 3, 1915 Serial No. 31,807.

An ordinaryaqueous solution-of gelatin may be first employed andthe remted or its equivalent maybe applied to or added to the subsequentcellulose solution but such prac-f tice has not been a as the employmentof a formicacid solution of'gelatin. r of practically any strength.taining 2% strong solution,

The gelatin solution may be say, a 15% solution, because it produces adesirably thin film on the plate. The gelatin solution may be spreadupon the clean glass in any suitable manner. For example,

period of time varying hour to several" hours,

depending on the Asolution congelatin is preferable over a it maybepoured upon flowed'uniformly over the glass, the excess; being pouredofi one corner ofthe plate and then set up on edge to drips While so arthe formic acid orjothersolvent will I the-finger without adhering,which condition obtains after a from lessthan a half foundas successful,(owin'gi poss1bly to the presence or actionof water) moisture of theair, the glass is ready fornthe next coating of cellulose material. Thecellulose material" may be prepared by dissolving 17 parts of celluloidin small piecesin a suitable solvent, such as acetone, in which case44.25 parts of acetone may be used, and adding to it, mixing thoroughlymeanwhile, a solution'of camphor in a suitable solvent for instance suchasmay ploying parts of camphor and 35,4: partsof the solutions should becontinued, their tembe made by em denatured alcohol; The mixing ofperature' being preferably maintained" at not,

exceeding 50 hasbeen formed; the mass is then filtered, as

6., until a homogeneous mass by beingforced throughaffelt'and-silk-tfiltransferring the cellulose material to the coated glass,

a vissolvent being employed, since this solvent acts merely as a vehiclefor Theeaddition of the camphori solution is not necessary but withcertain celluloids this-addition has beenfound to' be advantageous.Instead of celluloid, nitro-cellulose, with the addition of camphor, oracetate of cellulose or any other equivalent cellulose material may.beused. The formic acid may be incorporated, as stated above, with thecellulose material.

The viscous solution of cellulose material,

prepared in any of the above indicated ways,

is now placed upon the gelatin film hereinbefore described, and spreadthere-over in any suitable manner; the coating of cellulose material,and the first coating of gelatin also,

the plate when in a horizontal position and will overflow. if more-isaddedn Theplate is now allowed to stand'on a. l veled table in anatmosphere offa solve t nd out of contact with moisture. This may beaccomplished by surrounding theiplate by a glass topped frame, thespaces between the frame sides and .the cellulose-covered plate beingposed to the air,--for about twelve hours, the

' composite plate is removed to a suitable drylng chamber and kept therefor about three days, being subjected meanwhile to a bath of air atabout 20' to140 G. The solvents are thus removed and the plate is now ina finished condition and may be used either alone or combined in anysuitable manner with a protective material such as a second glassplate." For example; if two similar plates,

prepared as described, are desired to be combined, the cellulosesurfaces of the two plates may be placed in contact and the edges of theplates cemented together in any wellknown andsuitable fashion. If it isdesired to produce a glass of a particular color a suitable dye-stuflmay be added to the cellu- 101d solution or to the gelatin solution forthis purpose.

The product thus formed is characterized by great strength andresistance to shattering blows an'd'by the non-scattering of thefragments in case of the sheet being'broken. These characteristics areespecially pronounced because of the close adherence be- "tween thegelatin and cellulose films caused by the employment of a solvent suchas may be applied by hand or by suitabler mechanism. The'amount'ogfjinaterial used is preferably such as will completely cover 1said formic acid in one or theother'of the solutions applied, which is asolvent for both the gelatin and the cellulose material. The gelatinfilm when dried to the extent indicated, that is, to the point at whichthe finger when touched against the film will not sensibly adhere to it,contains suflicient traces of formic acid, which traces have a solventaction upon the celluloid film subsequently applied, whereby anintermingling of the two solutions in the region of their contact witheach other is produced which has the result of so uniting the two layersby an intermingling and interlocking, as it were, of their moleculesthatthe joining is not merely a surface adherence and that a great stress isrequired .to tear them apart.

I claim: p

1. The process of making non-scatterable glass which comprises applyingto a sheet of glass successively a solution of gelatin and a solution ofcellulose material, at least one bf said solutions containing a solventwhich has a solvent action upon both the gelatin and the cellulosematerial.

2. The process of making non-scatterable glass which comprisesv applyingto a sheet of glass a transparent gelatinous solution, a1-

lowing said solution to partially dry and then applying thereto asolution of cellulose material, at least one taining formic acid.

3. The process of making non-scatterable glass which comprises applyingto a sheet of glass'a' solution of gelatin dissolved in formic acid,allowing said solution to partially dry and then applying thereto a solution of cellulose material.

4c. The process of making non-scatterable glass which comprises applyingto a sheet of glass a solution of gelatin dissolved in formic acid,allowing said solution toparof said solutions con- 'tially dry and thenapplying thereto a solution of celluloid dissolved in'acetone.

5. The process of making non-scatterable glass which comprises applyingto a sheet of glass a gelatin coating and applying to gelatin coating acoating of cellulose material, there being present in theregion ofcontact of the two coatings a solvent for both. a

6. The process of making non-scatterable glass which comprises applyingto a sheet of glass a gelatin coating.and applying to said gelatincoating a coating of cellulose material, formic acid being present inthe region of contact of the two coatings.

7. A non-scatterable glass comprising a sheet of glass, a film ofgelatin thereon and a film of cellulose material on said gelatin film,the two films beinginterlocked in the region of their contact by asolvent common to both films.

8. A non-scatterable glass comprising a sheet of glass, at film ofgelatin there0n, a In testimony whereof I have hereunto set film ofcellulose material on said gelatin my hand in the presence of twosubscribing film, the two films being interlocked by-havwitnesses ingbeen dissolved into each other at the re- ANDRE ROOSEVELT. ,5, gion ofContact by a common solvent, and a Witnesses:

.protective material eoveringsaid film of cel- FRITZ ZIEGLEBW' J r.,

lulose material. J OHN A. FERGUSON.

Disclaimer in Letters Patent No. 1,210,987.

the formic acid or its equiva ent may be a plie DISCLAIMER.

1,210,987.Andr Roosevelt, New York, N. Y. NON-SOATTERABLE GLASS AND THEPnoonssor MAKING 11*. Patent dated January 2, 1917. December 19, 1918,by the-assignee, Glass Founders Corporation.

Enters its disclaimer to those portions of the specification, and tothat portion of the claim which is in the Iollowing'words, to wit:

Page 1, lines 3436: at least one of the solvents employed having asolvent action upon both the gelatin and the cellulose material."

' Same page, lines 51-62: Instead of formic acid an other solvent ofgelatin ma be used which also has solvent action upon the cellu osematerial subsequently lie used. An ordinary a ueous solution of elatinmaybe first employed and g to or added to the subsequent cellulosesolution but such practice has not een found as successful (owingpossibly tolthe presence or action of water) as the employment of aformic acid solution of e atin.

g Same p e, line 73: or other solvent.

P e 2,11nes 6-8: "The formic acid may be incorporated, as stated above,with the 0 close material."

Same page, lines 64-81: a solvent such as formic acid in one or theother of the solutions a plied, which is a solvent for both the elatinand the cellulose material. The go atin film when dried to the extent inicated, that is, to the point at which the finger when touched againstthe film will not sensibly adhere to it, contains sufficient traces offormic acid, which traces have a solvent action upon the celluloid filmsubsequently applied, whereby an inter-mingling of the two solutions inthe region of their contact with each other is produced which has theresult of so uniting the two layers by an intermingling andinterlocking, as it were, of their molecules that the joining is notmerely a surface adherence and that a great stress is required to tearthem apart.

l. The process of making non-scatterable glass which comprises applyingto a sheet of glass successively a solution of gelatin and a. solutionof cellulose material, at least one of said solutions containing asolvent which has a solvent action upon both the gelatin and thecellulose material.

2. The process of making non-scatterable glass which comprises applyingto a sheet of lass a transparent gelatinous solution, allowing saidsolution to partially dr and t on applying thereto a solution ofcellulose material, at least one of said so utions containing formicacid.

5. The process of making nou-scatterable glass which comprises applying,to a sheet of glass at elatin coating and appl ing to said gelatin,coating a coating of cellulose materia there being present in theregion of contact of the two coatings a sols out for both.

6. The process of making non-scatterable glass which comprises applyingto a sheet of glass aagelatin coating and applying to said gelatincoating a coating of cellulose materi formic acid being present in theregion of contact of the two coatm "7. i non-scatterable glasscomprising a sheet of lass, a film of latin thereon and a film ofcellulose material on said gelatin film, the two films being interlockedin the region of their contact by a solvent common to both films.

8. A non-scatterable glass comprising a sheet of glass, a film ofgelatin thereon, a film of cellulose material on said clatm film, thetwo films being interlocked b having been dissolved into each otfiier atthe region of contact by a common so vent, and a protective materialcovering said film of cellulose material.

[Ojic'ial Gazette, December 17, 1918.]

Disclaimer filed

